lkml.org 
[lkml]   [2013]   [Nov]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] gcc4: Disable __compiletime_object_size for GCC 4.6+
On Wed, Nov 13, 2013 at 10:39:13AM -0800, Kees Cook wrote:
> Hi Guenter,
>
> On Fri, Apr 12, 2013 at 07:49:08PM -0700, Guenter Roeck wrote:
> > __builtin_object_size is known to be broken on gcc 4.6+.
> > See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48880 for details.
> >
> > This causes unnecssary build warnings and errors such as
> >
> > In function 'copy_from_user', inlined from 'sb16_copy_from_user'
> > at sound/oss/sb_audio.c:878:22:
> > arch/x86/include/asm/uaccess_32.h:211:26: error: call to 'copy_from_user_overflow'
> > declared with attribute error: copy_from_user() buffer size is not provably correct
> > make[3]: [sound/oss/sb_audio.o] Error 1 (ignored)
> >
> > Disable it where broken.
>
> Is there an alternative? This means that things like
> DEBUG_STRICT_USER_COPY_CHECKS are being rendered useless. I don't think
> this is _always_ broken, just under certain situations, right?
>
There was a recent proposal to address the problem differently and then revert
this patch. Not sure what happened with it. I can try digging it up if necessary.

Guenter


\
 
 \ /
  Last update: 2013-11-13 22:01    [W:0.043 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site